<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta http-equiv="X-UA-Compatible" content="IE=edge">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
  <style>
    *{
      margin: 0;
      padding: 0;
      box-sizing: border-box;
    }
    .reminder{
      text-align: center;
      margin: 100px auto;
      font-size: 30px;
      width: 280px;
      color:gold
    }
    .background{
      position: fixed;
      top:0;
      bottom: 0;
      left: 0;
      right: 0;
      width: 100%;
      height: 100%;
      filter: blur(3px) opacity(0.2);
    }
    .close{
      position: absolute;
      font-size: 14px;
      color:dodgerblue;
      right: 30px;
      bottom: 30px;
      cursor: pointer;
      z-index: 1;
    }
  </style>
</head>
<body>
  <span class="close enable-click">知道了</span>
  <div class="reminder"></div>
  <div>
    <img class="background"/>
  </div>
  
  
</body>
<script>
  
</script>
</html>